21 Mar New nanotech approach could enable fast anthrax detection
(Click thumbnails for video) In each of these video clips, live bacteria are directed down a narrow channel to a pair of electrodes where they are trapped by mild electric currents. Courtesy of the Hamers Group.Taking a new approach to the painstaking assembly of nanometer-sized machines – much thinner than human hair – scientists at the University of Wisconsin-Madison have successfully used single bacterial cells to make tiny bio-electronic circuits.
The work is important because it has the potential to make building the atomic-scale machines of the nanotechnologist far easier. It also may be the basis for a new class of biological sensors capable of near-instantaneous detection of dangerous biological agents such as anthrax.
“One of the great challenges of nanotechnology remains the assembly of nanoscale objects into more complex systems,” says Robert Hamers, a UW-Madison professor of chemistry and the senior author of the new reports. “We think that bacteria and other small biological systems can be used as templates for fabricating even more complex systems.”
Toward that end, Hamers and his UW-Madison colleagues Joseph Beck, Lu Shang and Matthew Marcus, have developed a system in which living microbes, notably bacteria, are guided, one at a time, down a channel to a pair of electrodes. Researchers have the ability to capture, interrogate and release bacterial cells one by one.
Built into a sensor, such a capability would enable real-time detection of dangerous biological agents, including anthrax and other microbial pathogens.
The device could be constructed, according to Beck, utilizing the natural features bacteria and other microbes use to sense their environments. The wired bacterial cells, coupled with modern microelectronics, would have the ability not only to detect dangerous agents (anthrax spores, for example) but they then could sound the alarm and call for help.
The ability to routinely and easily capture and analyze individual microbes will have implications for conventional biotechnology as well. For example, chemical modifications to the electrode traps might make it easier for scientists to retrieve specified cells from a complex mixture.
The work by Hamers’ group was funded by the National Science Foundation. The Wisconsin Alumni Research Foundation, a private, nonprofit organization that manages UW-Madison intellectual property, has applied for patents for the technology.